Error semantics

Consider this pipeline of sequential steps:

<p:pipeline ...>
  <p:warning-a ...>

  <p:try>
    <p:group>
       <p:warning-b ...>
       <p:error ...>
    </p:group>
    <p:catch>
        ...
    </p:catch>
  </p:try>

  <p:warning-c ...>
</p:pipeline>

Where the "warning" steps write to their error port but don't fail.
The error step writes to its error port and fails.

If I read the errors in the catch, ...

 - [May I | Must I | Must I Not] see the warnings generated by warning-a?
 - [May I | Must I | Must I Not] see the warnings generated by warning-b?
 - [May I | Must I | Must I Not] see the warnings generated by error?

If I read the errors after warning-c, what can I/must I/must I not see?

                                        Be seeing you,
                                          norm

-- 
Norman Walsh <ndw@nwalsh.com> | A censor is a man who knows more than
http://nwalsh.com/            | he thinks you ought to.--Granville Hacks